1. Field of the Invention
The present invention relates to an automatic die changing apparatus of a die for rapidly performing a die changing of a die with respect to a molding machine.
2. Description of the Prior Art
Conventionally, for obtaining a die cast product having a large size and a complex structure such as a cylinder block, the die requires a slide. Accordingly, a whole of the die becomes heavy (196 kN (about 20 ton) for one example) and large in scale (about 2 m for one example), it is extremely troublesome to take out the die from the molding machine and it is necessary to take out and insert a tie bar connecting a fixed portion to a movable portion, so that there is a problem that an effect of shortening the die changing time is extremely small.
Further, a part of some work, for example, work for attaching and detaching a hose for a die cooling water and a cable for operation control with respect to the die are manually performed. That is, work performed by the die changing apparatus and the manual work are mixed. Further, at a time of the manual works, it is necessary to temporarily shut off a power source of the die changing apparatus completely. In order to safely perform the die changing work, the working procedure is expected to be careful.
The working procedure mentioned above of course requires a lot of time, and causes a decrease of operational availability in the molding machine. Further, in many cases, a portion to be repaired is only a portion constituting a product surface in a whole of the die in most cases, and a lot of time is required for work for taking out the whole of the die from the molding machine despite that such a repair is finished in a comparatively short time. Accordingly, this procedure is a major case for decreasing efficiency of the repairing work.
In this case, in a structure disclosed in Japanese Patent Laid-Open Publication No. 6-190531, only a part (a core) of the exclusive portion is replaced, with leaving the general portion in the molding machine, however, since a method of fastening the exclusive portion by bolts is employed, it is necessary to perform the fastening operation within the molding machine having a limited space, and a deterioration in operability and an unsafe operation can not be avoided. Further, since the exclusive portion is fastened by the bolts from a front surface thereof, it is impossible to apply the work to the exclusive portion in which the front surface constitutes the cavity forming surface, and an applicable range thereof is limited.
The problem mentioned above is not applied only to the die changing of a casting die, but is a common problem for dies in accordance with the other various casting methods and a die for resin molding. It is conventionally desired to achieve a more effective die changing work.